Properties of MatterSection 15.2

Warm up What is matter?What are the three states of matter?Fill in the tables with one difference between each

of the following:Element and compoundCompound and mixture

Objectives Identify substances using physical

properties.Compare and contrast physical and

chemical changes.Identify chemical changes.Determine how the law of

conservation of mass applies to chemical changes.

Introduction What properties can be used to describe the items

in the following figure?

Physical propertiesAny characteristic of a material that you can

observe without changing the identity of the substance.

Examples of physical properties are:

Color, size, shape, mass, volume, density, melting point, boiling point, attraction to magnet and the ability to flow.

Some physical properties describe the behavior of materials or substances.

Examples are copper and gold.

Using physical properties to separateHow can you separate a mixture of iron filling and

sand?How can you separate a mixture of seeds and

sand?

Physical change

Physical change

Use physical change to separate

Distillation

Chemical properties and changesA chemical property is a characteristic of a

substance that indicates whether it can undergo a chemical change.

Examples: flammability,

Detecting chemical changeChemical change: a change of one substance to

another.Examples of chemical change

Chemical change

Clues of chemical changeSmell, change in color formation of gasformation of a precipitatepop soundproduction of heat cooling formation of bubbles, light, foaming…

Using chemical change to separateCleaning tarnished silver.Tarnish is a chemical reaction between silver

metal and sulfur compounds in the air.We can remove tarnish by placing the tarnished

silver item in warm water, baking soda and aluminum foil.

Many metals are separated from their ores and then purified by using chemical changes.

The conservation of massMatter is neither created nor lost during a

chemical change.The mass of all substances that are present before

a chemical change equals the mass of all substances that remain after the chemical change.

Example: when a chemical reaction takes place, the total mass of reactants equals the total mass of products. If 18 g of hydrogen react completely with 633 g of chlorine, how many grams of HCl are formed?

H2 + Cl2 2 HCl

Wrap upWhat is a physical property?What is a chemical property?Distinguish between a physical and chemical

change.Examples of a physical and chemical change and

properties.Law of conservation of mass

Home Work

Page: 465 # 1 to 6Practice problem page: 463 # 1 and 2

Quiz in section 15.2